Colgate Directory

Amy Leventer

Amy Leventer: Research in Antarctica

Amy has led and participated in many cruises to Antarctica, commonly taking one or more Colgate students with her. One such cruise is described below.

CHAOS (Coring Holocene Antarctic Ocean Sediments)

From January 30 to March 29 2001, a team of 25 scientists, including Charlie McClennen and Amy Leventer (Chief Scientist), and Colgate undergraduate geology majors Natalie McLenaghan, Meredith Metcalf, and Caroline Olson, explored the East Antarctic Margin on cruise NBP0101 of the RVIB Nathaniel B. Palmer.

The Palmer is one of two icebreakers leased by the National Science Foundation and is dedicated almost entirely to conducting scientific research in the Southern Ocean. This 58-day cruise left from Hobart Tasmania and returned to port in Capetown South Africa, after transiting nearly a quarter of the way around the perimeter of Antarctica. Along the way, nearly a quarter mile of sediment core was recovered from seven deep shelf basins, with the goal of developing a record of climate and oceanographic change during the Quaternary.

Although the pace of recent climate change appears to be more rapid and of a larger scale in Antarctica compared to other areas of the globe, the factors forcing climate change in Antarctica are not well understood, due to the relative inaccessibility of the southernmost continent and the inhospitable working conditions. In order to address this scarcity of samples, particularly from the eastern side of the continent, we devoted our two months of ship time to acquiring as much data as possible.

Most of the sediment core material was recovered with the "Jumbo Piston Corer," a 90-foot long, 5" diameter, assembly of steel barrels, plastic core liner, and lead weights. Core sites were selected based on a combination of sub-bottom profiling and seafloor bathymetric mapping of well stratified and undisturbed acoustic reflectors. Back in the lab, our group has been responsible for two lines of investigation.

First, we develop paleoenvironmental reconstructions based on microscopic analysis of diatoms, single celled algae with a hard silica skeleton that serves as a permanent record of past climate. Second, we work with the sea floor maps to decipher the geologic processes that have shaped the seabed. Natalie, Caroline and Meredith worked with both Charlie and Amy as well as with our colleagues from other institutions, on senior projects based on the data collected during the cruise. Their contribution to the success of this cruise has been invaluable. Geology undergrads will continue the detailed analysis for the next few years as we extract the clearest indicators of Antarctic margin climate change from the core samples.